1. Field of the Invention
This invention relates to a thawing agent which can effectively prevent or remove freezing or snowdrifts of roads or on roofs, farm-land, etc., particularly to a thawing and antifreezing agent having great thawing and antifreezing effect and further having almost non-phytotoxicity.
Snow and ice are distributed on broad area of the earth in winter and interrupt normal traffics in that area and further, it not only makes farming works impossible but causes serious traffic accidents. In particular, in heavy snow teritories, snow usually gives damages on materials and mental and further impedes economical expansion at those territories because of rise in prices caused by interruption or delay of traffics and large expense to remove the drifted snow on roads or roofs, and moreover, lose in human lifes caused by traffic accidents, collapses of houses, etc.
2. Description of the Prior Art
As a countermove to the above snowdrift and freezing, there has usually been used sprinkling or spraying crude calcium chloride which is a by-product from Solvay soda process in the form of powder or concentrated solution, but this crude calcium chloride is at the most 70% or so purity. Thus, it cannot expect a sufficient antifreezing and thawing effect unless its frequent spreadings are done. Moreover, its spread in a large amount will severely injure plant or fresh water fishes and shells. Under such circumstances, the spread of calcium chloride has practically limited to main roads etc., but severe phytotoxicity to the planted trees at central separation zones and side zones thereof is usually seen. Although this phytotoxicity can be reduced by sufficient washing of the tainted trees at early spring on which the roots of the trees get into an action to absorb water in soil, such large scale washing the trees throughout the total length of long distance roads is practically impossible because of necessary water transport, much labour cost required, etc. In this connection, the superintendents of roads have been obliged to transplant withered trees at heavy expense every year.
The inventor has heretofore commented as to the defects of known thawing and antifreezing agents, in particular, as to their phytotoxicity. Besides, the known thawing and antifreezing agent has another defect of easy rust-forming which should not be overlooked. Owing to this defect, the cars that have run the road on which a thawing agent has been scattered must be washed well each time to exempt from rust formation and lowering of durable years caused thereby. Also, this embarasses the users in views of trouble and expense.